Improved mode of eemoviig tin fbom sheet metal



@iti-trs tetris @anni 't'fttg DQE. STURDEVANT AND 13.151'. HNRMON, or oLIEToNs'EEINes, NEW YORK.

Letters Patent No. 75,809, dated March 24, 1868.

. @Elie ttthtl referat 1t it tlgest 'tstter ttent ttt. flirting tart uf its tame -TO ALL WHOM IT MAY CON CERN V i l Be it known that we, D. B. STURDEVANT and B, H. HXBMON, of. Clifton Springs, in the county ot' Ontario, and State of New Yori?, have invented a certain new and usefuLMethod of Removing Tin Coatings from Sheet Metal; andwe do hereby declare'that the following'isa fulll and exact description thereof, reference being had to the accompanying drawings, makingpart of this specification. y

The figure represents a central vertical section ofl our improved apparatus'. I

y The object of this improvement is to remove tin coatings from sheet metal, such, for instance, as scraps, old tinware, dto.

The process covers the-combined Vemployment offsteam' and hot air, andthe apparatus consists of a retort, y having inductioand e'duction-air passages, a shakix1g-grate, and a contracted bottomyemployed in connection with a. water-receptacle beneath, for the generation of the'steam. I

In the drawings, A indicatesjthe retort, which'may rest upon afm-nace, B, or beotherwise connected with l any apparatus by which heat may be imparted. It has a cover, a, by which the sheet metal is4 inserted, and also l a grate', C, for sustaining the same, and allowing a free passage ofthe hot air and steam through. This grate 'is made t'o shake freely in the retort, `being preferably provided'witha hand-crank, b, extending out through theA sides. An induction hot-air pipe, D, opens beneath the grate',-and an,'eduction'-pipe, E, extends from above it, The bottom of the retort is in funnel-form, and has a small opening, c,'as showii, and beneath this opening rests `a. water-receptacle, G, for the generation of steam. v

l The operation is asfollows: The scraps of sheet metal are placed upon the grate, and hot airAlet on through pipe D, and steam vthrough orice e.- When heated, the grate is shaken, and: the particles of tin, as they are released, fall down through the open bottom into the receptacle beneath.

This combination of the principles ,of hot air and steam hasaispecial ef'ectfV inl removing and preserving coatings of tin.V The dry hot air loosens the coatings, while Athe'steam softens and retains the tin in its semiliquid form, after being loosened, till it finally escapes into the outside receptacle. Neitherl .could act'alone to" produce the desired resu-lt. Hot air`alone would, dry or harden the coating upon the body of the sheet metal itself, and alsocause it to adhere and deaden upon the vsides of the retort. Steam alone Wvould not have theV eifect to remove the tin. In combination the hot air reduces the tin, While the steam adds that fluidityv which Vis essential not only to'disengage the coatings from the dross, but also' to 'free the same from the retort itselfa i To `accomplish this the vapor constantly lls the vvhole Vinteriorpoi` the retort,` and permeates thoroughly the material, keepingthe whole lubricated or bathed insucha manner as to obviate sticking. While this action isl r .taking place lthe loose grate allows the mass to be thoroughly agitated, which is essential in the processtoprod duce a thorough removal of lthe tin. I

What we claim as our invention, and desire to secureby Letters Patent, is-

1. The process, h'erein described, of removing tin coatings from sheet metal, by the'combined use of hot-air and steam acting upon the mass in a closed retort, substantially as herein set forth.V I Y 2. We also claimnthe special combination and arrangement of the "apparatus for prodncingthe'res-ult, the' A vsame consisting of Vtire-,retort A, grate C, hot-air pipes D E, and Water-receptacle G, .the wholeoperating inthe `xannerand for the purpose hereinset forth. In witness whereof, we have hereunto signed our names Iinthe preseuceot` two subscribing witnesses.

D. B. STURDEVANT, B. H. HARMON.

Witnesses:

J. A. DAVIS, FRED.- A. HATCH. 

